Flow control devices, such as motor controlled electric valves may be provided in heating/cooling systems to control the flow of fluid through the system. For example, motor controlled valves may be used at nodes of diverging loops of circuits to provide refrigerant for heat reclaim or for defrosting evaporators. The motor controlled valves may include a piston which is movable by an electric motor to vary the flow of fluid through the valve. The motor may be rotated by a signal sent by a controller. The motor rotates a gear train that is coupled to the piston to cause the piston to move.